Marine sanitary devices in particular and waste disposal systems in general have been proceeding through an evolutionary process for a number of years. The Environmental Protection Agency (EPA) has issued various specifications regarding requirements for processing liquid and solid human waste as set forth in 33 C.F.R. 159. Sewage of waste disposal basically requires that, under certain circumstances, substantially all of the solid waste must be removed from any liquid discharged from the vessel. An additional requirement of EPA is to reduce fecal coliform bacteria to less than 200 count per 100 milliliters. In many instances recirculation of the fluid, for example water is desirable.
Separation of solid waste and collection can be accomplished in a variety of different well known manners. The difficulty resides in storage and disposal. Clearly improvements in this area are necessary particularly when stringent EPA sanitary regulations are taken into considerations and criteria such as size, cost and efficiency of operation are kept in mind.
Several effective systems are disclosed in commonly owned U.S. Pat. No. 4,393,524 and U.S. Pat. No. 4,519,103.
In addition to the factors taken in consideration in development of those systems, other factors also must be frequently considered. For example, in certain restricting and confined environments, storage of fluid such as water for use in the waste disposal system becomes burdensome and difficult. It would also be advantageous to minimize this difficulty whenever possible, for example, in geographic areas where a large volume of water is immediately and directly available, such as in marine environments like an ocean or a salt water lake. Accordingly, a system that would be designed to draw water directly from the external environment for use during a waste disposal sequence and then to discharge the water from the system back into the environment as acceptable effluent under EPA regulations would be extremely desirable. Elimination of a reservoir would reduce the size of the system and make it attractive to marine vessels where space is at a premium. With this same thought in mind, it would be helpful if the system could be designed in a modular fashion with many of the components designed as part of readily replaceable modules either for disposal of waste or replacement of components.